| Ginkgo biloba .L, a rare relict plant in the word, has an important value of research and exploitation. In this paper, origin center of Ginkgo was studied through palynology method, combining with research results of geology and archeology using seedling plant pollen of Ginkgo as experimental material, which tree age more than 100 years old in main production area of China. The research result provides palynology evidence for origin center of Ginkgo. Variation of nourishment composition in dormancy period of Ginkgo was probed by determination. And this result provided a theory for reasonable fertilization. P absorbing and distribution in Ginkgo was researched by 32P tracer technique, which result providing some scientific proof for fertilization and breeding in Ginkgo seedling period. The main results were showed as follow.1. There are specific pore and bump construction observed by SEM on the face of pollen grain. According to difference of pollen exine, pollen was classified 3 types, rough, smooth and middle. Individual form of Ginkgo pollen has significant differences by measure. It is performance of diversity of Ginkgo germplasm resources, and this diversity reflects genetype difference in different male plant in some degree.2. The result of energy spectrum analysis showed that C>O>P>Mg in pollen, and the content of the 4 elements collected from different place have obviously different each other.3. The cluster analysis was conducted to the results of shape observation and energy spectrum analysis. It can concluded, combining the results of cluster analysis with geology and archeology, that there were 3 possible origin center about Ginkgo,â… Southeast origin center,â…¡East origin center,â…¢north origin center.4. The result of nutrition mensuration in dormancy stage branches showed as follow: change trend of soluble sugar content in Ginkgo branch was rises first and fall later, and this trend was obviously in female plant than male. Soluble sugar content was higher in female plant than male, and highest in 1-year-old branch then 2 and then 3-year-old. Starch content varied trend was up-down-up. Opposite to soluble sugar content, it was higher in male plant. But there was no obvious difference between 1, 2 and 3 year-old branch. In male plant, protein content was up-down-up, but steady earlier and down later in female plant. Protein content was higher in male plant than female plant, highest in 3-year-old branch, lowest in 1-year-old branch.5. In leaf senescence phase, the varied trend of soluble sugar was down-up-down in male plant, starch and protein was down along. In 1-year-old branch, soluble sugar and starch content was higher than in 2-year-old.6. Absorbing and distribution of P in Ginkgo was researched by 32P isotope tracer. The results showed that: from first to the 7th day, 32P absorbing was increasing as long as cultivation, P absorbility rose to 4.56% from 2.63%. From the 7th day to the 14th day, it declined from 4.56% to 3.23%. The proportion of P distribution in every department was stem, lateral root, main root, leaf.
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